SOLAR ECLIPSE SAFARI - 2001 June 21

Byron Soulsby

Canberra Astronomical Society Incorporated

Abstract

Thirteen intrepid expedition members traveled to Zambia, in Africa to observe the total solar eclipse South of the centreline at a site near Mvuu. The site details for Mvuu from Peter's GPS were19 km from Mvuu, 075 degrees True (non-magnetic). At Latitude -15d 45.627m [actual reading at corner turnoff to Mvuu camping site was 15d 45m 28.74s] and 29d14.223m [29d 13m 52.74s]. The new USNO computed centreline for delta t = 64.3 seconds, was 25 to 26 km North of our site, viz. we were 25 to 26 km South of the new centreline. As a result, there were less Baily Beads seen and recorded on the video sound track on Tape 2 as our site was much closer to the new centreline than originally planned. My watch was 5 seconds FAST when compared to Peter's GPS time.

Instrumentation

Two instruments mounted on a small altitude-azimuth tripod were collimated by the use of sturdy brackets as shown below in the associated email message. The eclipse was observed using a Sony TE511E video camera with superimposed UT timing and audio recording, with the imaging undertaken without interruption for the complete eclipse from first to fourth contact. A two layer aluminised mylar solar filter was fitted on the two times Sony magnifying lens which was used before and after totality. During totality this filter was removed. All video imaging used manual focusing and manual exposure settings. In addition, a 400 mm focal length telephoto lens and 20 mm focal length orthoscopic eyepiece was used for direct viewing of Baily Beads before and after totality through a single layer of aluminised mylar which was also removed during the time of total eclipse.

A digital camera was used in an attempt to capture images from the 400 mm lens, but overexposure problems were encounter and the Ixus Cannon camera was unsuccessful.

Observations

 The video camera audio recording was the primary source of capturing the Baily Beads observed before and after totality through the 400 mm telescope, as it had been proven at the 1999 annular solar eclipse in Geraldton Western Australia, that the video camera's definition was not good enough to record the tiny points of light produced by the photosphere of the Sun when shining through the valleys of the Moon. Numerous beads were observed and the activity was recorded for later analysis by comparison with predictions from David Herald's Occult/Baily Beads software using the corrected GPS coordinates for our site near Mvuu.

Visual observation of the Sun in total eclipse was made through the 400mm telephoto lens and 20 mm orthoscopic eyepiece at around 30 times magnification. The image was crystal clear and three prominences were immediately seen at around 15 to 30 degrees position angle (PA), with a fourth very large prominence at 85 degrees PA followed by a fifth smaller prominence at 10 degrees PA. Filaments were not readily observed in the outer corona but were recorded on the video camera as shown in the associated images web page. This eclipse had far less emotional impact for me than my other successful solar eclipses seen in Indonesia and New Guinea.

Analysis

David Herald's Occult/Baily Beads software was used to produced timing predictions for beads at the corrected Mvuu site location:


Baily Beads Observed by Byron Soulsby on 2001 June 21 from Mvuu, Zambia Africa

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NEAREST

 

NEAREST

 

 

 

 

Time

Observed R

Predicted R

Observed L

Predicted L

 

 

 

R cusp is WA 33 to 107 degrees

 

L cusp is WA 107 to 145 degrees

 

 

 

13 h 08 m UT

 

 

 

 

 

 

 

7s

formed

07m 59s

 

 

 

 

 

 

22s

forming

08m 15s

 

 

 

 

 

 

29s

breaking

 

 

 

 

 

 

 

38s

very noticeable

08m 35s

 

 

 

 

 

 

42s

very strong bead

 

 

 

 

 

 

 

50s

slowly fading

 

 

 

 

 

 

 

53s

gone

 

 

 

 

 

 

 

13 h 09 m UT

 

 

 

 

 

 

 

13s

forming

09m 08s

 

 

 

 

 

 

15s

 

 

forming

 

 

 

 

 

16s

still forming

 

 

 

 

 

 

 

33s

broken

 

 

 

 

 

 

 

36s

bead

 

 

 

 

 

 

 

39s

starting to break

 

 

 

 

 

 

 

25s

bead

 

 

 

 

 

 

 

48s

just gone

 

 

 

 

 

 

 

58s

 

 

forming

 

 

 

 

 

13 h 10 m UT

 

 

 

 

 

 

 

01s

forming

 

 

 

 

 

 

 

07s

 

 

breaking, gone

 

 

 

 

 

23s

 

 

two beads forming

10m 24s

 

 

 

 

29s

 

 

another bead, gone

10m 29s

 

 

 

 

33s

 

 

another bead, gone

10m 33s

 

 

 

 

35s

whole string of 3 to 4

10m 35s

 

 

 

 

 

 

38s

many beads

10m 38s

 

 

 

 

 

 

41s

gone

 

 

 

 

 

 

 

44s

big beads

10m 44s

 

 

 

 

 

 

48s

gone

 

 

 

 

 

 

 

53s

another bead

 

 

 

 

 

 

 

56s

Totality for 3m 07s

 

Filters OFF

 

 

 

 

 

13 h 11 m UT

 

 

 

 

 

 

45s

 

 

large prominence

 

 

 

 

 

13 h 12 m UT

 

 

 

 

 

 

 

11s

many prominences 3

 

 

 

 

 

 

 

23s

one more prominence

 

 

 

 

 

 

 

13 h 14 m UT

 

 

 

 

 

 

 

03s

diamond ring

 

Filters ON

 

 

 

 

 

 

images lost

 

Images lost for 4 minutes

 

 

 

 

13 h 20 m UT

 

 

 

 

 

 

 

03s

regained images